Drum-type debarking apparatus

ABSTRACT

Debarking apparatus comprising a rotatably driven drum and an anvil inside of the drum circumferentially surrounded by the latter and operatively associated therewith for restricting log movement with the drum during the drum rotation. The drum carries debarking tool means in the form of a plurality of individual, blunt, debarking tool elements which are shown as arcuately contoured on all working sides, said debarking tool elements being arranged in sets extending at least generally circumferentially of the drum at locations spaced longitudinally thereof; and adjacent ones of such sets of tool elements are eccentric to one another and in circumferentially stepped relationship.

Young United States Patent [191 r Apr. 30, 1974 l DRUM-TYPE DEBARKING APPARATUS Filed:

Inventor: Douglas L. G. Young, Pierre Fonds,

Quebec, Canada Assignee: Canadian lngersoll-Rand Company Limited, Montreal, Quebec, Canada Oct. 16, 1972 Appl. No.: 297,777

US. Cl. 144/208 B, 241/182 Int. Cl. B211 1/00 Field of Search 144/208 R, 208 B, 309 R,

References Cited UNITED STATES PATENTS Wakeman 144/208 B Dick 144/208 B Ross 144/208 B Bache-Wiig.... 144/208 B Schnyder 144/208 B Primary EraminerAndrew R. Juhasz Assistant ExaminerW. D. Bray Attorney, Agent, or Firm-Robert R. Paquin; David W. Tibbott [5 7] ABSTRACT Debarking apparatus comprising a rotatably driven drum and an anvil inside of the drum circumferentially surrounded by the latter and operatively associated therewith for restricting log movement with the drum during the drum rotation. The drum carries debarking tool means in the form of a plurality of individual, blunt, debarking tool elements which are shown as arcuately contoured on all working sides, said debarking tool elements being arranged in sets extending at least generally circumferentially of the drum at locations spaced longitudinally thereof; and adjacent ones of such sets of tool elements are eccentric to one another and in circumferentially stepped relationship.

49 Claims, 9 Drawing Figures PATENTEB PR m4 Iii-807L470 SHEET 2 OF 3 00000 O OO Q Y F/a.4

Pmmrenmsom 3;807;470

SHEET 3 [IF 3 ll DRUM-TYPE DEBARKING APPARATUS Thepresent invention relates generally to debarking apparatus andmore particularly to debarking apparatus of the drum-type wherein logs are debarked in a rotatably. driven drum. 1 r I Commercially available, rotating drum-type debarking apparatus includes both traditional tumbling debarkers, usually employed for debarking pulpwood logs of up to eight feet in length, and more recently developed, rolling flow debarkers, usually employed for debarking pulpwood logs of eight feet and greater length.

Conventional tumbling debarkers are characterized by the drum carrying staves which are particularly adapted to provide mini'rnum slip between the drum 1 and its contained logs whereby, during drum rotation, the logs are caused to tumble in random manner while bark is removed due to the combined action of impact, compression and attrition primarily between the logs. Tumbling debarkers are unable to debark frozen logs and, whenfrozen wood is encountered, require that the outer layers of the logs be thawed either prior to, or during, the debarking. Typically, in North America this thawing of frozen logs to be debarked in tumbling debarkers is performed by providing the debarking drum with internal'hot water showers and/or log immersion sections while inEuropethe necessary thawing is usually performedupstream of the drum. 7 I r Effective debarking may be attained from tumbling debarkers particularly when such are accompanied by recirculation of only partially debarked logs back through the drum. However, tumbling debarkersareof undesireably limited capacity and their employment normally requires the use of multiple, parallel installed drums and associated wood handling equipment, thereby necesssitating relatively high capital and maintenance costs for their installation and operation. Furthermore, such'debarkers aresusceptible to breakage of small diameter logs, broomin'gof wood ends and sawdust loss and increased costs due to slashing of short length logs. In addition, the hot water showers and/or log immersion sections employed for providing the necessary thawing of frozen logs, create a myriad of problems in that the removed bark must be separated from the shower or immersion liquid prior to the burning of the bark and discharge of the liquid from the mill.

Conventional rolling flow debarkers are characterized by the drum carryinga larger number of staves of flatter, less aggressive profile adapted to permit slip between the logs and the drum; and, during the operation of such debarkers, the logs are maintained essentially parallel to the drum axis while a primarily rolling or spinning action is imparted to the logs to provide debarking by both log-to-log abrasion and log-to-dru'm abrasion. The drums of rolling flow debarkers have higher throughput rates than those of tumbling debarkers, thereby reducing wood handling costs. However, conventional rolling flow debarkers provide less effective bark removal than tumbling debarkers particularly with respect to irregular or small diameter logs. Also, rolling flow debarkers are of substantially higher capital costs than tumbling debarkers and are of relatively greater (for example, 150 to 200 foot) length. In addition, winter operation of rolling flow debarkers in cold climates again necessitates the thawing of the logs either prior to, or during, the debarking. Losses due to log slashing may be at least somewhat lower in rolling flow debarkers than in tumbling debarkers in some instances; and, although wood losses during the debarking operation may be lower in rolling flow debarkers than tumbling debarkers, it is believed that the amount of such lower wood losses is at least sometimes exaggerated.

Conventional, commercially available, tumbling debarkers and rolling flow debarkers all are limited to debarking a log of about twenty-four inches in maximum diameter; and larger softwood logs are usually individually debarked by ring debarkers, hydraulic jet debarkers or cutter head debarkers. Also, such conventional tumbling debarkers and rolling flow debarkers are not susceptible to relocatable installations, but rather require their employment in fixed installations. Moreover, although hardwood logs of certain species are sometimes debarked in either tumbling or rolling flow debarkers, the debarking of some major hardwood species (for examples, aspen) at certain times of the year requires the employment of hand peeling.

An object of the present invention is to-provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to provide relatively rapid, highly effective debarking.

Another object of theinvention is to provide new and improved rotating drum type debarking apparatus which is particularly constructed and arranged such that the debarking drum, for a given diameter and length, provides substantially greater debarking capacity than the drums of the before-described conventional debarking apparatus.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to permit construction of the debarking drum of substantially smaller diameter and/or length than possible in the beforedescribed conventional debarking apparatus of similar capacity.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularlyconstructedand arranged to readily debark logs, such as irregularly shapped and/or hardwood logs, currently believed to be difficult to debark.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to readily debark frozen logs without the necessity for liquid defreezing of the logs, thereby avoiding the problems inherently arising in the event of such liquid defreezing.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged, to be capable of employment in either relocatable or fixed embodiments.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to reduce wood loss during debarking due to positive orientation of the logs and relatively short retention time in the drum.

Another object is to .provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to be rotatably driven at relatively rotary high speed.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particu larly constructed and arranged to debark logs of substantially any desired length.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to provide highly effective debarking while substantially minimizing or eliminating the necessity for log recirculation back through the debarking drum.

Another object is to provide new and improved rotating drum-type debarking apparatus which is particularly constructed and arranged to, for the debarking capacity of the drum, require only a relatively economical wood handling system.

Another object is to provide new and improved drum-type debarking apparatus which is particularly constructed and arranged to posess only relatively low power requirements.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein, as will be understood, the preferred embodiments of the invention have been given by way of illustration only.

In accordance with the invention, debarking apparatus may comprise drum means, anvil means within the drum means operatively associated therewith for restricting log movement with said drum meansduring the rotation of said drum means, the drum means being rotatable relative to the anvil means for applying high unit pressure, localized impact blows to logs in said drum means during the rotation thereof, and debarking tool means carried by the drum means within the drum means, such debarking tool means being arcuately contoured on all working sides and being illustrated as particularly arranged to debark irregularly shapped logs.

Referring to the drawings:

FIG. 1 is an elevational side view of a debarking apparatus constructed in accordance with one embodiment of the invention;

FIG. 2 is a elevational end view showing the inlet end of the debarking apparatus illustrated in FIG. 1;

FIG. 3 is an enlarged elevational sectional view of such debarking apparatus taken on line 3-3 of FIG. 1, looking in the direction of the arrows;

FIG. 4 is an enlarged, fragmentary, longitudinal sectional view of the debarking apparatus illustrated in FIGS. 1 through 3;

FIG. 5 is an enlarged, fragmentary sectional view of said apparatus taken on line 5-5 of FIG. 3, looking in the direction of the arrows;

FIG. 6 is a schematic view illustrating the relative arrangement of four adjacent ones of the sets of tool elements carried by the drum of such apparatus;

FIG. 7 is a perspective view illustrating the relative arrangement of the avnil means and debarking tool mounting means of the FIG. 1 apparatus;

FIG. 8 is a view schematically illustrating the relative arrangement of the anvil means and debarking tool mounting means of the FIG. I apparatus; and

FIG. 9 is a fragmentary view illustrating an alternative form of anvil means for use in the debarking appa- -ratus shown in FIG. 1.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, FIG. 1 illustrates a debarking apparatus comprising an elongated, rotatable, debarking drum 10 which is at least generally horizontal although, if desired, angled downwardly from its inlet end towards its discharge end 12b to facilitate the passage of logs longitudinally therethrough. The drum 10 includes an inlet section 14, located adjacent the drum inlet end 12a, and a debarking section 16 which is unitary with the inlet section 14. The drum inlet section 14 is formed from an imperforate rolled plate and intended only for introducing logs into the drum 10. The drum debarking section 16 is illustrated as formed from a plurality of coaxial ring supports 18 spaced apart longitudinally of the drum 10 by therebetween bark discharge openings 20, and longitudinally extending channels 22 circumferentially spaced around the ring supports 18 and interconnecting the latter. As will be understood, however, the debarking section alternatively could be formed from annular plate or of other construction, providing that suitable bark discharge openings are therein provided. Also, although not shown, the drum inlet section 14 could, if desired, be provided with helical or other suitable means for facilitating the flow of logs therethrough.

The drum 10 includes a pair of annular tires 24, rigidly mounted circumferentially around the channels 22 at locations spaced apart longitudinally of the drum 10, and is ground supported by pairs of rotatable trunnion rollers 26 rotatably engaging each of the tires 24. The drum 10 rigidly carries a circumferential toothed gear 28 intermeshing with a driving pinion 28a and is rotatably driven therethrough by a conventional driving motor 30 which is connected to the pinion 28a through a conventional speed reducer 30a. The motor 30 is suitably sized to rotatably drive the drum l0 loaded with logs at a relatively high rotary speed within the range of, for example, twenty to one-hundred revolutions per minute. The direction of this drum driven rotation, as viewed in FIGS. 2, 3, 7, and 8, is counterclockwise and schematically depicted by the arrows shown adjacent the drum circumference in such FIGS. It will be understood however that, although the drum 10 has been shown as so supported and rotatably driven, such has been done only for the purposes of illustration; and, alternatively, the drum 10 could be otherwise wise suitably supported and rotatably driven at the beforementioned relatively high rotary speed.

The debarking apparatus further comprises stationary or non-rotatable log supply and discharge sections 32,34, respectively, adjacent the inlet and discharge ends l2a,l2b of the drum 10. The stationary log supply section 32 is ground mounted by a supporting pedestal 36 and contains a supply chamber 38 at one open end to the interior of the drum inlet section 14 for supplying unbarked logs thereto. The other end of the inlet chamber 38 is of reduced cross-section and communicates through a relatively small diameter inlet opening 40 with a conveyor 42 or other source of logs 44 to be debarked; and the supply chamber 38 progressively increases in cross-section to the full cross-section of the interior of the drum inlet section 14 as it extends from the inlet opening 40 towards the inlet section 14. The stationary discharge section 34 is ground mounted by a supporting pedestal 46 and contains a discharge chamber 48 at one end open to the interior of the drum discharge end 12a for discharging debarked logs therefrom. Adjacent its other end, the discharge chamber 48 includes a portion progressively narrowing in crosssection; and at its said other end the discharge chamber 48 terminates in a relatively small discharge opening 50 communicating with a discharge chute 52 adapted for discharging debarked logs 54 therefrom. Alternatively, as will be understood,either or both of the supply and discharge sections 32, 34 may be carried by the drum for rotation therewith rather than being stationary and separate from the drum l0.

The drum debarking section 16 isprovided with relatively blunt debarking tools or tool elements 56 particularly constructed for applying high intensity, hammerlike impacts to logs passingthrough the debarking section. 16 during the relatively high speed driven rotation of the drum 10. The tool elements 56 serve to debark the logs and also cause log rotation and a transverse pattern of circulation of the logs resulting in repeated presentation of varying parts of the logs to the tools 56.

As illustrated, the debarking tools 56 are in the configuration of generally hemispherical protrusions, arcuately contoured on all working sides to minimize wood damage, which are sufficientlysmall to provide high unit pressure, localized impact blows to the logs during the debarking operation. By way of example, the arcuately contoured working surface 56a of each tool element 56 could be of three-eights to one-half inch radius for a 34 inch diameter experimental drum and one to one and one-quarter inch radius for a 6 foot diameter drum, that is of a radius of around approximately onefiftieth to one-hundredth of the drum diameter. As will be understood, the debarking tools 56 could be of other than generally hemispherical configuration providing that'their dimensions longitudinally of the drum 10 are maintained only a relatively small or minor portion. of the length of the logs to be debarked whereby they are enabled to provide said high unit pressure, impact blows to the logs. 'Also,although not'shown, the de' barking tools 56 could be of different sizes at different locations in the drum 10. For example, the tools 56 adjacent the inlet section 14 ofthe drum 10 could be of smaller size than the others thereof with the size of the tools 56 progressively increasing from the drum inlet section 14 towards the drum discharge'end 12b.

The debarking tools 56 are particularly arranged to provide random impacts to logsv passing through the drum 12 as well as to debark hollow or recessed portions of the logs. More specifically, as illustrated, an annular eccentric mounting plate 58 of continuously varying radial cross-section is affixed along its outer circumference to the inner circumference of each ring support 18. Moreover, adjacent ones of the mounting plates 58 longitudinally of the drum 10 are circumferentially offset whereby the most radially enlarged portions 58a of such adjacent plates 58 extend arcuately along successive arcuate segments of the drum circumference and longitudinally overlap for minor portions of their lengths. The inner circumference of each mounting plate 58 has affixed thereto an annular tool mounting ring 60, spaced by a space 62 from each of the thereadjacent ones thereof; and each tool mounting ring 60, in turn, carries an arcuate tool mounting segment 64, shown for the purposes of illustration as being of around one hundred degrees in arcuate length, which is located to extend along the most radially enlarged portion 58a of the'corresponding mounting plate 518. Each tool segment 64 along its inner circumference carries a set of debarking tools 56, each such set of the tools 56, as illustrated, comprising a plurality of generally circumferentially arranged rows of the tools 56 and justaposed rows of the tools 56 of each set thereof "ral pattern.

As will be seen, the illustrated arrangement of the tool mounting segments 64 causes adjacent ones thereof to extend arcuately along successive arcuate segments of the drum inner circumference and longitudinally overlap for a minor portion of their arcuate lengths. Hence, as shown in FIGS. 4 and 6, throughout the length of the debarking section 16, adjacent onesof the sets of tools 56 are resultantly caused to similarly extend around successive arcuate segments of the drum inner circumference and overlap circumferentially of the drum 10, whereby the sets of the tools 56 are in circumferentially stepped relationship. Also, due to the beforedescribed arrangement of the tools 56, the tools 56 are eccentric to the drum 12; and sets of the tools 56 at different locations longitudinally of the drum 10 are eccentric to one'another. As a result, the tools 56 are unusually effective in debarking hollow or recessed portions of logs and provide random impacts to the logs during the drum rotation.

The debarking apparatus further includes anvil means within the drum 10 circumferentially surrounded by the latter and preventing rimming of logs with the drum 10 during the relatively high speed drum driven rotation (that is, restricting log movement with the drum 10 during its rotation by preventing logs from being carried completely around the inner circumfer ence of the drum 10) while further, controlling the velocity of the transverse circulation of the logs, thereby maximizing the relative velocity of the tools 56 and the log mass and also maximizing the forces between the tools 56 and the log mass. Such maximizing of said relative velocity and said forces by the anvil means has been found to substantially increase the effectiveness of the bark removal and the capacity of the apparatus for any given size drums As illustrated, this anvil means comprises an elongated anvil, designated generally as 66, which longitudinally extends through the interior of the drum l0 and is rigidly connected at opposite ends to the supply and discharge sections 32,34, respectfully. (As will be understood, in the event that the sections 32,34 were rotatable with the drum 10, the opposite ends of the anvil 66 could be mounted to stationary mounting frames on the opposite sides of the sections 32,34.) Hence, the anvil is normally held in fixed position during operation of the apparatus. Alternatively, however, as will be understood, the anvil 66 could be pivotally mounted either for adjustment or free swinging movement during the operation of the apparatus, the drum 10 again, of course, being rotatable relative to the anvil 66.

As shown in FIGS. 3 and 7, the anvil 66 projects through the upper half of the interior of the drum 10 and is in the portion of such upper half leading in the direction of the drum driven rotation. It will be understood, however, that the anvil 66 could be otherwise suitably located internally of the drum 10, but preferably is in the upper half of the drum 10 to permit maximum drum loading and maximize the unit pressure with which the debarking tools 56 impact the logs.

Throughout the portion of the anvil 66 internally of the debarking section 16, the anvil 66 includes an outwardly facing, upper, generally convex, surface 68 opposing the inner circumference of the drum 10. The anvil 68 is spaced from the drum carried rotating components of the apparatus by an arcuate space 70 sufficient to permit rotation of such components relative to the anvil 66; and the space 70 preferably progressively increases in the direction of the drum driven rotation to permit log fragments of small diameter to readily escape therefrom. As best shown in FIGS. 7 and 8, at intervals throughout the portion of its length internally of the debarking section 16, the anvil 66 comprises integral depending comb-like portions 72 projecting generally radially outwardly intermediate each of the adjacent ones of the mounting plates 58. The comb-like portions 72, as will be understood, prevent small diameter logs from entering the space 70.

The lower side of the anvil 66 includes an at least generally downwardly facing portion 74 which is particularly constructed for controlling the transverse circulation of the logs in the debarking section 16, to cause logs emerging from the top of the therebelow log pile to roll downwardly along the free surface, designated generally as 76 in FIG. 3, of the log pile. The portion 74 thus prevents the logs emerging from the top of the log pile from being thrown outwardly above the free surface 76, and causes the weight of the emerged logs to act through the log pile to increase the debarking forces between the tools 56 and the there-adjacent logs. in addition, the portion 74 controls the velocity at which logs emerge from the top of the log pile in the transverse circulation of the logs and thereby controls both the velocity of the logs adjacent the tools 56 and the relative velocity of the tools 56 and logs.

The lower side of the anvil 66 includes an at least generally downwardly facing portion 78, at least partially defined by the comb-like portions 72, which insures smooth flow of successive logs of varying diameters in the transverse circulatory pattern of the log movement. More particularly, the portion 78 serves to prevent the entrapment of smaller diameter logs at the location indicated generally as 80 in FIGS. 3 and 8, which entrapment might otherwise occur in the event that a small diameter log at said location were followed by a succession of larger diameter logs in the circulatory pattern. The portion 78 performs this function due to its location above the center of the drum 10, its length transversely of the drum and its angle relative to the surface 74. The actual length of the portion 78 and said angle thereof will, of course, vary in different embodiments of the invention dependent upon the nature of the logs to be debarked and the size and capacity of the drum 10. However, as shown in FIG. 8 wherein the inner and outer positions of the rotating eccentric parts of the drum 10 are designated as 82 and 84, respectively, the angle of the surface 78 relative to the surface 74 may be around and preferably is between l2 and 25. The remaining portion 86 of the lower side of the anvil 66 preferably slopes upwardly from the portion 74 and may be of substantially any desired configuration not interfering with the transverse log circulation and providing the anvil 66 with appropriate strength and stiffness.

As shown in FIG. 9, the lower side of the anvil 66 may be provided with ribs 88 or other means adapted for facilitating log movement longitudinally through the debarking section 16, the ribs 88, as illustrated, being located at intervals along such anvil lower side.

Throughout the operation of the debarking apparatus, the drum l0 and its carried debarking tools 56 are rotatably driven relative to the anvil 66 at a relatively high rotary speed (for example 20 to 100 revolutions per minute) by the motor 30. The logs 44 to be debarked may be either continuously or intermittently supplied by the conveyor 42 through the supply chamber 38 in the supply section 32 to the inlet section 14 of the rotating drum 10 and the debarked logs 54 are discharged from the discharge end 16 of the drum 10 to the discharge chute 52 through the discharge chamber 48 in the discharge section 34.

lntemally of the debarking section 16 of the rotating drum 10, the tools 56 debark the logs by applying high intensity, hammer-like impacts thereto and also cause rotation and the beforedescribed transverse circulation of the logs. The tools 56, due to their arrangement, moreover, readily debark irregularly shaped logs while, as the logs are maintained at least substantially parallel to the drum axis, wood losses due to brooming are substantially minimized. The anvil 66 controls the transverse circulatory velocity of the logs and the transverse pattern of log flow, thereby maximizing the debarking effect by maintaining maximum relative velocity between the tools 56 and the logs and maximizing the forces between the tools 56 and the adjacent logs. The anvil 56, moreover, prevents logs from entering the space and insures uniform flow free from interference by the formation of log structures at 80. The bark removed from the logs in the debarking section 16 is rapidly discharged therefrom by the bark discharge openings 20, thereby preventing the bark from interfering with the bark removal processes; and the entire debarking process, including the debarking of frozen logs, can be performed without the necessity for thawing.

From the preceeding description it will be seen that the invention provides new and improved means for accomplishing of the beforestated objects and advantages. It will be understood, however, that although only two embodiments of the invention have been illustrated and hereinbefore specifically described, the invention is not limited merely to these embodiments, but rather contemplates other embodiments and variations within the scope of the following claims.

Also, it will be further understood that the apparatus of the invention could be employed for both delimbing and debarking of appropriate species of trees.

I claim:

1. Debarking apparatus comprising drum means, anvil means inside of said drum means operatively associated therewith for restricting log movement with said drum means during the rotation of said drum means, said drum means being rotatable relative to said anvil means, and debarking tool means carried by said drum means Within said drum means for applying high unit pressure, localized impact blows to logs in said drum means during the rotation thereof, said debarking tool means being accurately contoured on all working sides.

2. Debarking apparatus according to claim 1, wherein said anvil means is adapted to create transverse log circulation in said drum means and to cause logs to roll downwardly across the free surface of a therebelow log pile.

4. Debarking apparatus according to claim 1, wherein said anvil means is adapted to prevent build-up of log structure s adjacent to said drum means.

5. Debarking apparatus according to claim 1, wherein said debarking tool means comprises tool element means eccentric to said drummeans.

6. Debarking apparatus according to claim 1, wherein said debarking tool means comprises tool element means arranged at least generally circumferentially of said drum means at locations spaced longitudinally thereof.

7. Debarking apparatus according to claim 6, further comprising said tool element means being eccentric at said spaced locations.

8. Debarking apparatus according to claim 1, wherein said debarking tool means comprises a plurality of individual tool elements at locations spaced longitudinally and circumferentially of said drum means.

9. Debarking apparatus according to claim 8, wherein said tool elements each are, longitudinally of said drum means, only a minor portion of the length of logs to be debarked.

l0. Debarking apparatus according to claim 8, further comprising mounting means extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof mounting said tool elements on said drum means, said anvil means including portions projecting intermediate adjacent ones of said mounting means.

l1. Debarking apparatus according to claim 1, wherein said debarking tool means comprises a plurality of sets of tool elements extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof.

12. Debarking apparatus according to claim 11, wherein said sets of tool elements include sets thereof eccentric to said drum means.

13. Debarking apparatus according to claim 12, wherein said sets of tool elements include sets thereof eccentric to one another.

14. Debarking apparatus according to claim 11, wherein said sets of tool elements each extend around only a portion of said drum means.

15. Debarking apparatus according to claim 14, wherein adjacent ones of saidsets of tool elements overlap circumferentially of said drum means.

16. Debarking apparatus according to claim 14, wherein adjacent ones of said sets of tool elements extend around successive portions of the circumference of said drum means.

17. Debarking apparatus according to claim 16, wherein adjacent ones of said sets of tool elements overlap circumferentially of said drur'n means.

j 18. Debarking apparatus according to claim 14, wherein said sets of tool elements include sets thereof eccentric to one another.

19. Debarking apparatus according to claim 12, further comprising arcuate mounting means mounting said tool elements on said drum means, said anvil means including portions projecting between adjacent ones of said mounting means.

20. Debarking apparatus according to claim 1, wherein said anvil means is non-rotatable at least during normal operation of the apparatus.

21. Debarking apparatus according to claim 1, wherein said anvil means extends longitudinally through said drum means and is supported at opposite ends thereof. I

22. Debarking apparatus according to claim 21,

wherein said drum means is at least generally horizontal and said anvil means is in the upper half of said drum means.

23. Debarking apparatus according to claim 1, wherein said anvil means includes an at least generally downwardly facing anvil surface.

24. Debarking apparatus according to claim 23, wherein said anvil surface is adapted to control the relative velocity of said debarking tool means and logs in said drum means during rotation of said drum means.

25. Debarking apparatus according to claim 23, wherein said anvil surface is adapted to create transverse log circulation in said drum means and to cause logs to roll downwardly across the free surface of a therebelow log pile.

26. Debarking apparatus according to claim 23, wherein said anvil surface is adapted to prevent buildup of log structures adjacent to said drum means.

27. Debarking apparatus according to claim 1, wherein said anvil means includes first and second at least generally downwardly facing anvilsurfaces, said first anvil surface being adapted to control the relative velocity of said debarking tool means and logs in said drum means duringrotation of said drum means, said first anvil surface also being adapted to create transverse log circulation in said drum means and to cause logs to roll downwardly across the free surfaceof a therebelow log pile, and said second anvil surface being adapted to prevent build-up of log structures adjacent to said drum means.

28. Debarking apparatus according to claim 27, wherein said second anvilsurface is angled relative to said first anvil surface.

29. Debarking apparatus according to claim 27, further comprising mounting means extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof mounting said debarking tool means on said drum means, said anvil means including portions intermediate adjacent ones of said mounting means, and said second anvil surface being on said projecting portions of said anvil means.

30. Debarking apparatus according to claim 1, further comprising means associated with said anvil means for facilitating log movementlongitudinally through said drum means.

31. Debarking apparatus according to claim 30, wherein said log movement facilitating means comprises rib means carried by said anvil means.

32. Debarking apparatus according to claim 1, further comprising means adjacent one end of said drum means providing a supply chamber communicating with such end of said drum means for supplying logs thereto, said supply'chamber including at least a portion progressively increasing in cross-section as it extends towards said drum means end.

33. Debarking apparatus according to claim 1, further comprising means adjacent one end of said drum means providing a discharge chamber communicating witth such end of said drum means for discharging logs therefrom, said discharge chamber including at least a portion progressively decreasing in cross-section as it extends from said drum means end.

34. Debarking apparatus according to claim 1, further comprising means adjacent one end of said drum means providing a supply chamber communicating with such one end of said drum means for supplying logs thereto, said inlet chamber including at least a portion progressively increasing in cross-section as it extends towards said one end of said drum means, and means adjacent the other end of said drum means providing a discharge chamber communicating with such other end of said drum means for discharging logs therefrom, said discharge chamber including at least a portion progressively decreasing in cross-section as it extends'from said other end of said drum means.

35. Debarking apparatus according to claim 34, wherein at least one of said mentioned chamber providing means is non-rotatable during rotation of said drum means.

36. Debarking apparatus according to claim 1, wherein said debarking tool means comprises a plurality of sets of tool elements extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof, said sets of tool elements each extend around only a portion of said drum means, said sets of tool elements include sets thereof eccentric to one another and sets thereof eccentric to said drum means, said drum means is at least generally horizontal, and said anvil means extends through the length of said drum means and includes an at least generally downwardly facing anvil surface throughout the length of said drum means.

37. Debarking apparatus according to claim 36, wherein adjacent ones of said sets of tool elements extend around successive arcuate portions of said drum means.

38. Debarking apparatus according to claim 36, wherein successive ones of said sets of tool elements overlap circumferentially of said drum means.

39. Debarking apparatus according to claim 36, further comprising annular mounting rings mounting said tool elements on said drum means said anvil means at intervals along its length including portions projecting intermediate adjacent ones of said mounting rings.

40. Debarking apparatus according to claim 39, wherein said anvil means is in the upper half of said drum means and is normally non-rotatable during operation of the apparatus.

41. Debarking apparatus comprising drum means and debarking tool means carried by said drum means within said drum means, said debarking tool means comprising a plurality of sets of tool elements extending at least generally circumferentially of said drum means at locations spaced longitudinally of said drum means, and said sets of tool elements each extending around only a portion of the circumference of said drum means.

42. Debarking apparatus according to claim 41, wherein adjacent ones of said sets of tool elements extend around successive segments of the circumference of said drum means.

43. Debarking apparatus according to claim 42, wherein adjacent ones of said sets of tool elements overlap circumferentially of said drum means.

44. Debarking apparatus according to claim 41, wherein said sets of tool elements include sets thereof eccentric to one another.

45. Debarking apparatus according to claim 41, wherein said sets of tool elements include sets thereof eccentric to said drum means.

46. Debarking apparatus according to claim 45, wherein adjacent ones of said sets of tool elements extend around successive portions of the circumference of said drum means and overlap circumferentially of said drum means.

47. Debarking apparatus according to claim 46, wherein said tool elements are arcuately contoured on all working sides.

48. Debarking apparatus comprising drum means, a plurality of debarking tool elements carried by said drum means Within said drum means for applying high unit pressure, localized impact blows to logs in said drum means during rotation thereof, said debarking tool elements being accurately contoured on all working sides, and anvil means inside of said drum means for controlling the relative velocity of said debarking tool elements and logs in said drum means during rotation of said drum means, said drum means being rotatable relative to said anvil means.

49. Debarking apparatus according to claim 48, wherein said anvil means is non-rotatable at least during normal operation of the apparatus, and said debarking tool elements are at locations spaced longitudinally and circumferentially of said drum means.

222 83 TED STATES PATENT OFFICE QERTIFICATE OF CORRECTION Q Patent No. 3,807,470 Dated April 30, 1974 Inventor(s) Douglas Young It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

E' Column. 2, line 43, cancel "shapped" and substitute shaped-- Column 3, line 16, cancel "posess" and substitute --possess-- lines 28-30, cancel "for applying high unit pressure, localized impact blows to logs in said drum means during the rotation thereof" line 32, immediately before the comma, insert -for applying high unit pressure, localized impact blows to logs in said drum means during the rotation thereof-- line 34, cancel "shapped" and substitute ---shaped--- 9 line 54, cancel "avnil" and substitute -anv1l- Column 4, line 42, cancel "wise" 7 Column 5, line 23, cancel "eights" and substitute ---eighths--- line 67, cancel "justaposed" and substitute --juxtaposed-- Q Column 8, line 38, cancel "preceeding" and substitute ---preceding line 60, cancel "accurately" and substitute --arcuately- Column 10, line 47, immediately after "portions" insert --projecting--- Q Column 12, line 38, cancel "accurately" and substitute -arcuately-- Signed and Sealed this 0 twenty-sixth Day Of August 1975 [SEAL] Attest:

a RUTH c. MASON c. MARSHALL DANN Allesting Officer Commissioner nj'lalents and Trm/emarkx 

1. Debarking apparatus comprising drum means, anvil means inside of said drum means operatively associated therewith for restricting log movement with said drum means during the rotation of said drum means, said drum means being rotatable relative to said anvil means, and debarking tool means carried by said drum means within said drum means for applying high unit pressure, localized impact blows to logs in said drum means during the rotation thereof, said debarking tool means being accurately contoured on all working sides.
 2. Debarking apparatus according to claim 1, wherein said anvil means is adapted to create transverse log circulation in said drum means and to cause logs to roll downwardly across the free surface of a therebelow log pile.
 3. Debarking apparatus according to claim 1, wherein said anvil means is adapted to control the relative velocity of said debarking tool means and logs in said drum means during rotation of said drum means.
 4. Debarking apparatus according to claim 1, wherein said anvil means is adapted to prevent build-up of log structures adjacent to said drum means.
 5. Debarking apparatus according to claim 1, wherein said debarking tool means comprises tool element means eccentric to said drum means.
 6. Debarking apparatus according to claim 1, wherein said debarking tool means comprises tool element means arranged at least generally circumferentially of said drum means at locations spaced longitudinally thereof.
 7. Debarking apparatus according to claim 6, further comprising said tool element means being eccentric at said spaced locations.
 8. Debarking apparatus according to claim 1, wherein said debarking tool means comprises a plurality of individual tool elements at locations spaced longitudinally and circumferentially of said drum means.
 9. Debarking apparatus according to claim 8, wherein said tool elements each are, longitudinally of said drum means, only a minor portion of the length of logs to be debarked.
 10. Debarking apparatus according to claim 8, further comprising mounting means extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof mounting said tool elements on said drum means, said anvil means including portions projecting intermediate adjacent ones of said mounting means.
 11. Debarking apparatus according to claim 1, wherein said debarking tool means comprises a plurality of sets of tool elements extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof.
 12. Debarking apparatus according to claim 11, wherein said sets of tool elements include sets thereof eccentric to said drum means.
 13. Debarking apparatus according to claim 12, wherein said sets of tool elements include sets thereof eccentric to one another.
 14. Debarking apparatus according to claim 11, wherein said sets of tool elements each extend around only a portion of said drum means.
 15. Debarking apparatus according to claim 14, wherein adjacent ones of said sets of tool elements overlap circumferentially of said drum means.
 16. Debarking apparatus according to claim 14, wherein adjacent ones of said sets of tool elements extend around successive portions of the circumference of said drum means.
 17. Debarking apparatus according to claim 16, wherein adjacent ones of said sets of tool elements overlap circumferentially of said drum means.
 18. Debarking apparatus according to claim 14, wherein said sets of tool elements include sets thereof eccentric to one another.
 19. Debarking apparatus according to claim 12, further comprising arcuate mounting means mounting said tool elements on said drum means, said anvil means including portions projecting between adjacent ones of said mounting means.
 20. Debarking apparatus according to claim 1, wherein said anvil means is non-rotatable at least during normal operation of the apparatus.
 21. Debarking apparatus according to claim 1, wherein said anvil means extends longitudinally through said drum means and is supported at opposite ends thereof.
 22. Debarking apparatus according to claim 21, wherein said drum means is at least generally horizontal and said anvil means is in the upper half of said drum means.
 23. Debarking apparatus according to claim 1, wherein said anvil means includes an at least generally downwardly facing anvil surface.
 24. Debarking apparatus according to claim 23, wherein said anvil surface is adapted to control the relative velocity of said debarking tool means and logs in said drum means during rotation of said drum means.
 25. Debarking apparatus according to claim 23, wherein said anvil surface is adapted to create transverse log circulation in said drum means and to cause logs to roll downwardly across the free surface of a therebelow log pile.
 26. Debarking apparatus according to claim 23, wherein said anvil surface is adapted to prevent build-up of log structures adjacent to said drum means.
 27. Debarking apparatus according to claim 1, wherein said anvil means includes first and second at least generally downwardly facing anvil surfaces, said first anvil surface being adapted to control the relative velocity of said debarking tool means and logs in said drum means during rotation of said drum means, said first anvil surface also being adapted to create transverse log circulation in said drum means and to cause logs to roll downwardly across the free surface of a therebelow log pile, and said second anvil surface being adapted to prevent build-up of log structures adjacent to said drum means.
 28. Debarking apparatus according to claim 27, wherein said second anvil surface is angled relative to said first anvil surface.
 29. Debarking apparatus according to claim 27, further comprising mounting means extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof mounting said debarking tool means on said drum means, said anvil means including portions intermediate adjacent ones of said mounting means, and said second anvil surface being on said projecting portions of said anvil means.
 30. Debarking apparatus according to claim 1, further comprising means associated with said anvil means for facilitating log movement longitudinally through said drum means.
 31. Debarking apparatus according to claim 30, wherein said log movement facilitating means comprises rib means carried by said anvil means.
 32. Debarking apparatus according to claim 1, further comprising means adjacent one end of said drum means providing a supply chamber communicating with such end of said drum means for supplying logs thereto, said supply chamber including at least a portion progressively increasing in cross-section as it extends towards said drum means end.
 33. Debarking apparatus according to claim 1, further comprising means adjacent one end of said drum means providing a discharge chamber communicating witth such end of said drum means for discharging logs therefrom, said discharge chamber including at least a portion progressively decreasing in cross-section as it extends from said drum means end.
 34. Debarking apparatus according to claim 1, further comprising means adjacent one end of said drum means providing a supply chamber communicating with such one end of said drum means for supplying logs thereto, said inlet chamber including at least a portion progressively increasing in cross-section as it extends towards said one end of said drum means, and means adjacent the other end of said drum means providing a discharge chamber communicating with such other end of said drum means for discharging logs therefrom, said discharge chamber including at least a portion progressively decreasing in cross-section as it extends from said other end of said drum means.
 35. Debarking apparatus according to claim 34, wherein at least one of said mentioned chamber providing means is non-rotatable during rotation of said drum means.
 36. Debarking apparatus according to claim 1, wherein said debarking tool means comprises a plurality of sets of tool elements extending at least generally circumferentially of said drum means at locations spaced longitudinally thereof, said sets of tool elements each extend around only a portion of said drum means, said sets of tool elements include sets thereof eccentric to one another and sets thereof eccentric to said drum means, said drum means is at least generally horizontal, and said anvil means extends through the length of said drum means and includes an at least generally downwardly facing anvil surface throughout the length of said drum means.
 37. Debarking apparatus according to claim 36, wherein adjacent ones of said sets of tool elements extend around successive arcuate portions of said drum means.
 38. Debarking apparatus according to claim 36, wherein successive ones of said sets of tool elements overlap circumferentially of said drum means.
 39. Debarking apparatus according to claim 36, further comprising annular mounting rings mounting said tool elements on said drum means, said anvil means at intervals along its length including portions projecting intermediate adjacent ones of said mounting rings.
 40. Debarking apparatus according to claim 39, wherein said anvil means is in the upper half of said drum means and is normally non-rotatable during operation of the apparatus.
 41. Debarking apparatus comprising drum means and debarking tool means carried by said drum means within said drum means, said debarking tool means comprising a plurality of sets of tool elements extending at least generally circumferentially of said drum means at locations spaced longitudinally of said drum means, and said sets of tool elements each extending around only a portion of the circumference of said drum means.
 42. Debarking apparatus according to claim 41, wherein adjacent ones of said sets of tool elements extend around successive segments of the circumference of said drum means.
 43. Debarking apparatus according to claim 42, wherein adjacent ones of said sets of tool elements overlap circumferentially of said drum means.
 44. Debarking apparatus according to claim 41, wherein said sets of tool elements include sets thereof eccentric to one another.
 45. Debarking apparatus according to claim 41, wherein said sets of tool elements include sets thereof eccentric to said drum means.
 46. Debarking apparatus according to claim 45, wherein adjacent ones of said sets of tool elements extend around successive portions of the circumference of said drum means and overlap circumferentially of said drum means.
 47. Debarking apparatus according to claim 46, wherein said tool elements are arcuately contoured on all working sides.
 48. Debarking apparatus comprising drum means, a plurality of debarking tool elements carried by said drum means within said drum means for applying high unit pressure, localized impact blows to logs in said drum means during rotation thereof, said debarking tool elements being accurately contoured on all working sides, and anvil means inside of said drum means for controlling the relative velocity of said debarking tool elements and logs in said drum means during rotation of said drum means, said drum means being rotatable relative to said anvil means.
 49. Debarking apparatus according to claim 48, wherein said anvil means is non-rotatable at least during normal operation of the apparatus, and said debarking tool elements are at locations spaced longitudinally and circumferentially of said drum means. 